(a) Field of the Invention
The present invention provides an optical transformation device able to transform a projected light beam from a spot light source to form rectangular projection surfaces, in which the transformation device transforms a three-dimensional conical illumination light shape into a pyramid shape, thereby enabling illuminating projection surfaces almost equal to a rectangular plane.
(b) Description of the Prior Art
The illumination angle of a light beam emitted by illuminating apparatus must be standardized, only then can the luminous flux be made to effectively converge on projection surfaces requiring illumination. For example, a traditional light bulb must use a lampshade for the purpose of backlight reflection, thereby enabling a light beam to converge towards the required illumination surface (projection surface). Moreover, recently, light beams are produced from diode light emitting devices, in which a microminiature reflecting surface is first located at the inner rear of a diode light emitting crystal body, thereby enabling the light beam produced by the crystal sphere to be projected frontward. In addition, because the curvature specifications of the reflecting surface enables the light beam produced by the light-emitting diode to be effectively controlled at the required angle, such as 15, 30, 45, 60 degrees, and which emitting angle to use can be decided upon according to requirements of the location where implemented.
Regardless of whether a traditional light bulb or the more recent LED (light-emitting diode) light source is used, the stimulated light spot is a spot light source, and the light shape, after reflection from a reflecting cover, is conical in form, moreover, the illumination projection surface mapped out is either a circular area or an ellipsoidal area. If implemented in a particular location, such as a street or road surface or square floor space of a home, in order to effectively assemble a luminous flux of the light source for use thereof, the shape of the light beam must be transformed, such as transforming the light shape into a pyramid shape, thereby enabling specifying the bottom surface of the light beam (projection surface) to be rectangular or square shaped.